PROTECTING PRIVATE WELL USERS’ HEALTH: RESULTS FROM TWO STATEWIDE STUDIES

Twenty-one percent of Minnesotans (1.2 million people) get their drinking water from a private well. Unlike people on a public water system, private well users (PWUs) are responsible for ensuring their water is safe to drink. To provide more accurate guidance on arsenic testing and treatment and to develop more effective outreach to PWUs, Minnesota Department of Health (MDH) conducted two studies in 2016. This presentation will discuss the main findings from the studies and how this information can be used to protect PWUs’ health.

• Arsenic Study: About 130,000 Minnesota PWUs consume water from a private well that has levels of naturally-occurring arsenic above the Safe Drinking Water Act standard of 10 micrograms per liter (µg/L). Drinking water with arsenic in it can lead to long-term adverse health effects. MDH collaborated with the Unites States Geological Survey to better understand how water sampling methods, location, and timing contribute to arsenic concentration results in a new well. The study found that how and when the initial sample is collected affects how accurately the sample result reflects the long-term arsenic level. The study also found that arsenic levels are just as likely to increase as decrease within the first year after construction. These results provide guidance on how to get an accurate test result for the long-term arsenic level in well water. An accurate test result helps PWUs make informed decisions about if and how they will reduce their exposure to arsenic.
• Private Well Household Survey: MDH surveyed 798 households with private wells that had arsenic levels above 10 µg/L to find out if they took any action to reduce their exposure to arsenic and learn about their general well stewardship practices and preferences. The survey found about one-third of the households had not taken any action to reduce their arsenic exposure and over 80 percent did not test their water at the frequency MDH recommends. Survey responses highlight various barriers and challenges that prevent or discourage PWUs from testing and treating their water. Demographic and socio-economic factors were found to be important predictors of behavior and preferences. The results also show the important role local partners play in protecting the health of PWUs.